Is your cat urinating or defecating outside of the litter-box?  House-soiling behavior in cats is a complicated issue.  There are several possible underlying issues including medical problems such as kidney disease, urinary tract disease, thyroid disease, and diabetes to name a few.  In some cases there are underlying environmental and social factors keeping cats out of the litter-box. There are several ways to treat inappropriate elimination, and the first step is to identify the underlying cause.  One step toward finding out what's wrong is to answer the “Cat Owner Questionnaire” about your cats behavior.   Completing this form and bringing it to your appointment will help your veterinarian thoroughly assess your cat.  

Check out for more information:  http://www.catvets.com/public/PDFs/ClientBrochures/HouseSoiling-WebView.pdf

 Cat Owner Questionaire